Induction meter



Dec. 23, 1930. H. FRCHLICH ETAL INDUCTION METER Filed July 19, 1928 I )uvzwrans Patented Dec. 23, 1930 UNITED-STATES rAraar @F FicE Hans ronHLIoHANn' WERNER ZINGG, or zoo, SWITZERLAND, ASSIGNORS To LANDIS .dc GYR, A .-G.,,A JOINT- STOCK COMPANY OF SVfI'iZER-LAND, .01 ZUG,

SWITZERLAND rnnucrron METER 7 Application filed July 19, 1928, Serial N 0. 293,939, and in Switzerland The invention relates to new and useful improvements in inductionmeters, and more especially to such improvements-in the, driv a ing systems of induction metersi Objects'and advantages ofthe invention will be set. forth in part hereinafterand in part =Wil'l; be obvious herefrom, orxmay be learned by practice with theinvention, the

' same being realized and attaine'd by means the instrumentahtles and combinations of pointed out in theappended claims.

The lnvention consists 1n the novel parts, constructions, arrangements, combinations and improvements: herein shown and described. V 1

The accompanying drawings, referred to herein and constituting a parthereof, illustrate one embodiment of the invention, and together with the description, serve to'explain the principles of the invention.

Of the drawings:

Fig. 1 is a perspective view of a mechanism embodying the invention;

Fig. 2 is a front elevation. of a different form of embodiment of the invention; and V Fig. 3 is a transverse section on line 33 of Fig. 2.

In induction measuring instruments the driving torque for the meter disc or equivalent element is effectedby two driving fluxes, which are displaced relatively to each other both in position and in phase. The torque is generally proportional to the product of said driving fluxes and to the sine of the angle of lag between the two fluxes.

A chief desideratum in the production, design and construction of induction meters is to obtain the greatest possible torque effect with the least possible amount of material and the least possible consumption of energy. The arrangement of the coils, the shape and location of the poles and of the driving disc, together with the materials employed, are all important factors in attaining more orrless completely to the desired efficiencies indicated. I

WVith the enumerated objects in view, the present'invention provides a novel pole. terminal'or attachment for pole terminals. According to said feature of our invention, one

7 core terminal,

I the a is produced with September 9, 1927. I

or more poles of either the pressure magnet or current magnet or both, is provided with a flat plate of ferromagnetic metal, preferably an iron alloy, which plate is of greater than the end of the pole piece and is magnetically connected to thepole piece or preferably by being fixed directly thereto.

By utilizing such a plate of relatively large area with respect to the area of the end of the pole terminal and magnetically connected to the pole, the resistance or reluctance of the magnetic circuitof the current flux is reduced. Experiments with such devices have disclosed stonishing fact or result that the torque, produced is quite considerably increased. In addition to the reduction of the magnetic reluctance, this increase in torque is apparently in part also obtained by reason of the fact that the driving flux and therewith the disc currents in the extension plates or pieces of the poleterminals are adjusted relatively'to the other driving fluxes in such manner that a maximum driving effect is obtained. 7

' Furthermore, the described enlargement of the pole terminal causes an increase in the cross-section of the magnetic circuit in the air gap, which'as previously indicated causes a reduction of the magnetic reluctance. Consequently adriving flux of a given magnitude a smaller number of ampere turns used for the excitation of the magnet. An appreciable economy in copper is thus made possible in the construction of the coil. The distribution over a larger surface of the'driving flux, that is, 'a'flux which passes through the drivingdisc, has the furtheredvantage that the braking effect of the flux, which is incident to induction measuring instruments With rotating systems, is reduced. The reason for this is that the. braking eflect is proportional to the R. P. M. and also'to the square of the braking flux; or with the same total braking flux to the square of the specific density thereof. This braking effect of the driving flux is a disturbing factor, since it causes, with larger loads, a drop in the curve of error. According to our invention, as will be understood from the foregoing, the enlargement'of the poles of the drivvided with worm 20 for ing magnet or magnets reduces the specific density of the driving fluxes and thereby also minimizes this disturbing factor. The materials employed in the pole enlarging plates is an important factor, and according to present preferred practice, we employ plates of various iron alloys.

Referring now in detail to the embodiment of the invention illustrated in Fig. 1, the pressure core 1 has the pressure coil 2 wound upon the limb 3 thereof. The limb of the core is fixed to a bracket plate 5, which in turn is tired to the plate 6 of the meter frame construction. Connected to the lower part on the limb t of the pressure core is a counter pole 7, which extends outwardly adjacent to the opposite side of the meter disc in a well-known manner.

The meter disc l is shown mounted on a spindle 16 having a screw-threaded top hearing 17 mounted in a plate 18, fixed to and extending outwardly from the top limb or reach 19 of the pressure core. the spindle is prodriving the register. At its lower end the spindle is journaled in a bearing 21, mounted in a supporting plate 22, which is fastened to the outer side of the current magnet.

The current magnet 27 is shown of U shape and is provided with two spaced-apart, upwardly-extending limbs 28 and 2 carrying the current coil winnings 30 and 31.

To the ends of the poles 28 and 29 are fastened the pale enlarging plates 33 and 3d, of alloy ferromagnetic metal, these poles being of larger area than the ends of the magnet poles to which they are directly in contact and attached by suitable means, such as screws 35.

Referring now to the embodiment of the invention shown in Figs. 2 and 3 on the drawings, the invention is shown applied to a different construction of driving magnets for the meter. In this form a pressure core 40 has a central limb ll and substantially parallel side limbs 42 and l3, a pressure coil 4A being wound upon the central limb 41. The central limb ll is provided with an enlarged head 45. A lag plate 46 is also attached to the voltage core.

The meter disc 48 is fixed upon a spindle L9, journaled at its upper end in a screw-threaded support 50, mounted in a bracket 51, fixed to the meter frame 52. The spindle is provided with a worm 53 for driving the register. At its lower end the spindle is journaled in a screw-threaded support 56, mounted in a bracket plate 57, fixed to the meter frame 52.

The pole enlarging plates 69 of alloy ferro magnetic metal are fixed directly in contactwith the end faces of the poles 64L and 65 of the current magnet, by screws 70, and are of larger area than the end faces on the poles and are magnetically connected thereto.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What we claim is 2- 1. An induction meter including in combination a meter disc, magnetic driving means therefor including pole enlarging devices comprising plates of magnetic material of greater area than the end face of the magnet pole pieces, secured to and completely overlying the end faces of the pole pieces and extending beyond the outside edges of adjacent pole pieces and away from each other.

2. An induction meter including in combinaton a meter disc, magnetic driving means therefor including voltage and current magnets and pole enlarging devices comprising plates of magnetic material of greater area than the end faces of the pole pieces of the current magnet, secured to and extending beyond the outside edges of adjacent pole pieces any away from each other.

3. An induction meter including in combinaton a meter disc, pressure and current magnets forming magnetic driving means therefor and including pole enlarging plates formed of alloy iron attached to and completely overlying the end faces of the current pole pieces and extending beyond the outside edges of adjacent pole pieces and away from each other.

In testimony whereof we have signed our names to this specification.

HANS FRoHLIoH. WERNER ZINGG. 

